This invention relates to a composition of matter which may be added to conventional allyl diglycol carbonate resins to impart a colorless appearance to optically clear allyl diglycol carbonate articles such as lenses and lens blanks produced therefrom.
Allyl diglycol carbonate resins have been extensively used to form optically clear, ophthalmic quality lens blanks and lenses. While such resins provide a highly desirable material for manufacturing such articles, they are characterized by a faint but obviously noticeable yellow color which makes them readily distinguishable from glass. Attempts to formulate prepolymer mixtures which appear "colorless" when polymerized have not been successful. The term "colorless" as used hereinafter, refers to a glass-like appearance, i.e., a very slight bluish tinge such as that possessed by glass lenses when viewed from the side.
Furthermore, with the increase in the number of allyl diglycol carbonate ophthalmic quality lenses manufactured, it has become increasingly more difficult for any one manufacturer to identify his products after sale. In this regard, it would be highly desirable for an individual manufacturer to be able to quickly and easily identify his products from those of competitors when a lens is returned for repair or replacement.
The composition of matter of the instant invention, when incorporated into conventional allyl diglycol carbonate articles, not only imparts the desired colorless appearance, but also imparts a faint but distinct ultraviolet activated fluorescence to the product which enables simple and rapid identification thereof.